Richard Dawkins

UNWEAVING THE RAINBOW

Science, delusion and the appetite for wonder

The title of this book comes from Keats, who believed that Newton had
removed the magic from the rainbow by explaining its colours
scientifically. Dawkins argues, persuasively in my view, that Keats had
it precisely wrong. But this view of science was quite common in
the nineteenth century (William Blake was a prominent exponent) and it
is if anything gaining ground today.

Dawkins makes a good job here of showing such views to be the nonsense
they are. Written with his usual clarity and elegance, the book looks at
how knowledge of the way things work in nature is truly a source of
wonder. The tone is nicely judged—never ranting or aggressive—and
there are plenty of well-chosen quotations that make the case neatly
from within the literary world itself.

Dawkins looks first at the eponymous rainbow, starting with the physics
of light and going on to discuss colour vision. Light can be thought of
as a form of vibration, and so can sound, which is the subject of the
next chapter. Dawkins applies the metaphor of barcodes to both of
these, and it can also be used to refer to DNA, which is treat in
another chapter.

Dawkins is well-known for his hostility to bogus claims for the
paranormal, and there are chapters on this and on why it is that people
are so easily deceived into believing in the unreal. This leads into the
subject of apparent coincidences and the difficulty which most of us
experience in forming correct intuitions about probability.

I thought the later chapters in the book were the most interesting. I
liked the discussion of what Dawkins calls bad poetic science. Stephen
Jay Gould figures largely here as an exemplar of the genre (he and
Dawkins were often at loggerheads). The topics in dispute include the
significance of discontinuities in the fossil record and differences of
interpretation of the "Cambrian explosion". Dawkins says that there must
logically have been creatures prior to the Cambrian that didn't
fossilize, and these may go far back in time before the Cambrian. But
the notion of an "explosion" persists. "Doubtless it has great poetic
appeal."

Two chapters are about genes as selfish replicators, and here there is
again (fairly gentle) debunking of bad poetic science. One example is
the claim that we should take the peaceable and sex-mad bonobo as a role
model instead of the more aggressive common chimpanzee. The whole idea
of using animals as role models is fundamentally wrong, Dawkins
believes.

Another cited example of bad poetic science is James Lovelock's "Gaia"
hypothesis. "[T]he whole rhetoric of Gaia is superfluous and misleading.
You don't need to talk about bacteria working for the good of anything
other than their own short-term genetic good." I'm not sure that he is
entirely fair to Lovelock here, but there is no doubt that the Gaia idea
has spawned a huge amount of sentimentality and bogus science in other
quarters.

The book concludes with a chapter looking at the perennial mystery of
the evolution of the human brain. What drove this dramatic development?
We don't know the answer, but Dawkins has a stimulating discussion. The
invention of language is his favourite candidate for what may have
driven the expansion of our brain, and I was particularly pleased to
find that he refers here to one of the most fruitful ideas I have seen,
namely Terrence Deacon's meme-like approach to the evolution of language
as described in his book The Symbolic Species